Underground securing system comprising a rock bolt that includes an attachment device

ABSTRACT

The invention relates to a securing system for the roof ( 10 ) of an underground road, said securing system comprising a rock bolt ( 1 ) to which a mobile attachment device ( 20 ) can be secured, said attachment device ( 20 ) being connected to the rock bolt ( 1 ) so as to be freely rotatable relative to the rock bolt ( 1 ).

The invention concerns a fastening system on the gallery roof of a route section underground or in tunnel construction, where the fastening system includes a rock bolt to which an anchor device is fixed.

Rock bolts are sufficiently known from the state of the art of the technology. Concerning that, WO 2012/053965 A1 is referred to as an example. Rock bolts usually consist of an anchor rod which protrudes into the gallery roof where an anchor plate is attached end-sided on the anchor rod with an anchor nut. With the aid of these rock bolts, the route section is secured in the area of the working face and gallery roof. The falling down of plate-shaped rock formations, or also salt layers, should be prevented by such rock bolts in particular. This means that such rock bolts are used for the stabilization of the route sections.

Now it is also known from the state of the art of the technology to use rock bolts as load anchors and to attach load carrying supports (e.g. lugs for the attachment of loads) to such rock bolts for this purpose. In the simplest case it is planned that, from the rock bolt, a part of the anchor rod provided with a screw thread protrudes from the gallery roof, to which the corresponding load-carrying supports are bolted with an internal thread. Such load-carrying supports serve for the fixing of loads, such as e.g. utility supply lines (pipes), power cables or also lighting equipment. From this it is clear that the area of application of such rock bolts is diverse.

For the attachment of this type of rock bolt, both in the working face as well as a gallery roof area, equipment devices are known which enable the incorporation of such anchors from the ground.

In case of the assembly or dismantling of systems, or also in case of repair and maintenance work, above a height of 1 m working height underground, a proper protection against fall of the persons working there is to be carried out.

One possible procedural method, e.g. in order to guarantee a fall protection in case of the installation or dismantling of systems, is that the persons are lifted to the working height with the aid of a lifting platform with corresponding rail, in order to enable the corresponding work to be carried out. These and also other technical measures for protection against fall from a height (such as e.g. the structuring of scaffolds) are in-part very extensive and difficult to apply environmentally-related or also dependent on the situation.

In order to now enable a fall protection for the persons carrying out the work which is usable with a low outlay, but which is effective and satisfies the requirements of occupational safety, the subject of this invention is a fastening system for arrangement on the gallery roof underground. A fastening system as a fall protection which satisfies the requirements of occupational health and safety is characterized invention-related by the characteristics of claim 1.

The subject of the invention is accordingly that the anchor device for the rock bolt is connected pivoting with the rock bolt. This against the following background: The persons who carry out the assembly work move and under certain circumstances are also rotated around their own axis.

In particular the person ensured by the anchor device can swing on the safety line in case of a fall from a height. As a result of the anchor device being freely pivoting on the rock bolt (rotation swirl function) the hazard does not exist that they rotate off from the rock bolt if the secured person is connected with the anchor device over a harness with the corresponding components by a spring hook.

For the above demonstrated reasons it is prohibited that persons secure themselves by means of spring hooks on the load carrying supports which are fixed, or become fixed, on the rock bolt for the reception of loads. The lug described in WO 2012/053965 A1, as previously dealt with, is connected directly and not freely pivoting by a screw thread with the actual rock bolt and is therefore unsuitable as a fall protection.

Basically the invention-related fastening system can therefore be used in every case where a personal protection is necessary against fall from a height. This is the case at a working height above one meter, when other safety devices are not existing or, dependent on the situation, are difficult to use.

Advantageous characteristics and structuring of the invention result from the subordinate claims.

Thus it is in particular planned that the anchor device indicates a screw-in sleeve for the connection with the rock bolt. An advantage here is the screw-thread connection between the rock bolt and the planned anchor element, where a so-called self-locking screw thread is inserted, in particular as screw thread, for example in the form of a trapezoidal thread.

This is in order to avoid a rotating-off of the screw thread. In detail the anchor device is characterized by a screw-in sleeve with internal thread, where the screw-in sleeve can be screwed onto the anchor rod of the rock bolt.

Furthermore, an advantage is that it has a shoulder for the reception of a sleeve-shaped swirl unit, where the swirl unit indicates an inset-attachment element, e.g. in the form of a strap, where the inset-attachment element serves for the reception of, for example, a spring hook of the protective harness of the person fixed to it. According to an especially advantageous characteristic, it is planned that a bearing is arranged between the shoulder and swirl unit, in particular an axial ball bearing, which minimizes the friction between the sleeve-shaped swirl unit on the one hand, and the shoulder on the screw-in sleeve on the other hand. Conceivable, however, is not only the employment of a thrust bearing in the form of a ball bearing, but also the employment of a corresponding plain bearing. In this way the situation is achieved where the swirl unit can rotate freely with small frictional forces, without the anchor sleeve detaching from the anchor rod of the rock bolt.

According to a further advantageous characteristic, it is planned that a bolt head for the bedding of a tool is arranged on the shoulder of the screw-in sleeve. The bolt head can be developed in this case similar to the tip of a screwdriver, by which the possibility is provided to screw the limit-stop lug onto the anchor rod of the rock bolt from the ground with the aid of a bar and the corresponding screw-on equipment, which indicates end-sided a tool head U-shaped in the cross-section for the reception of the bolt head.

According to a further advantageous characteristic of the invention, it is planned that the anchor device has an indication element for the determination of the screw-in depth of the screw-in sleeve on the anchor rod of the rock bolt.

This means that, as a result of this indication element, it is made identifiable to the person who implements the screwing of the anchor device onto the anchor rod of the rock bolt from the ground with the aid of the previously-designated bar that, for a secure attachment of the anchor device on the rock bolt, the screw-in sleeve and anchor rod of the rock bolt are connected with each other with a corresponding number of turns of the thread. In particular it is planned that the screw-in sleeve and anchor rod are connected with each other over at least four turns of the thread. The number of turns of the thread can also vary dependent on the anchor characteristics.

In this case, the indication element is developed in particular as a pin, where the pin is seated in a bore in the bolt head and/or in the shoulder of the screw-in sleeve and extends with one end into the hollow space of the screw-in sleeve. The fixing of the indication element in the anchor device is implemented force-locking, for example using friction. From this it is clear that the dimension with which the pin extends into the screw-in sleeve determines the minimum screw-on depth of the anchor sleeve on the threaded bolt of the rock bolt. This is because, in case of reaching the corresponding screw-on depth, the pin is forced out from the bore by the anchor rod of the rock bolt; it drops out (possibly caught by an arrest wire that is held with a ring fastener on the anchor device), and the person who carries out the screwing on of the anchor device can identify that the corresponding minimum screw-on depth has been reached.

This means that, for the protection of persons who work at greater heights, the procedure is now as follows: The rock bolt indicates a threaded piece extending beyond the rock. The invention-related anchor device is screwed onto this threaded piece with the corresponding screw-on equipment, possibly with the aid of a correspondingly long bar, e.g. a telescopic tube.

After that the spring hook is connected possibly with the same bar with the inset-attachment element (e.g. in the form of a strap) of the anchor device. Then the ascent to working height can begin.

The anchor device can be used repeatedly.

By means of the drawings, the invention is explained in more detail with examples.

FIG. 1 indicates a side view in the section on the fastening system, therefore the anchor device 20 with the rock bolt seated in the rock bolt 1;

FIG. 2 indicates a view in accordance with the Line II-II from FIG. 1.

The rock bolts designated in total with 1 include the anchor rod 8 from which a part 3 protrudes free downward from the gallery roof. In the area of the transition to the gallery roof 10 an anchor plate 5 is fixed on the protruding part of the anchor rod 3 with the aid of an anchor nut 4, which construction protects the gallery roof 10. The fixing of the rock bolt 1 in the rock is not dealt with in any detail at this point. The subject of the invention is now the rock bolt 1 in connection with the anchor device 20 and the anchor device itself. The anchor device 20, which can also be designated as a limit stop lug, includes a screw-in sleeve 22, where the screw-in sleeve 22 is provided with an internal thread 26, where the screw-in sleeve 22 indicates a shoulder 28 end-sided. On the shoulder 28 is located the bolt head 30 (e.g. developed like the tip of a screwdriver), where the bolt head 30 of the connection with screw-on equipment serves to enable the screwing on of the screw-in sleeve 22 with the internal thread 26 on the protruding part of the anchor rod 3 of the rock bolt 1 from the ground.

The anchor element designated with 40 includes the screw-in sleeve 22 with the shoulder 28, the bolt head 30 and the ball bearing 44, as well as the swirl unit 24.

On the shoulder 28 rests the sleeve-shaped swirl unit designated with 24. The swirl unit 24 indicates a movable strap 42 as an inset-attachment element, which serves for the attachment of for example a spring hook of the protective harness of the person e.g. working with the installation of loads. Between the front side of the sleeve-shaped swirl unit 24 and the shoulder 28 on the screw-in sleeve 22 is located for example an axial ball bearing 44, so that the friction between the swirl unit 24 and the shoulder 28 is decreased if the swirl unit 24 rotates around the screw-in sleeve 22 fixed-connected with the shoulder 28. In this respect a slight radial separation distance exists between the sleeve-shaped swirl unit and the screw-in sleeve, The screw-in sleeve 22 is secured with the swirl unit 24 by a retaining ring 27 e.g. in the form of a snap ring.

The shoulder 28 and the bolt head 30 on the screw-in sleeve 22 have a bore 34. The bore 34 is used for the reception of a pin 36 as an indication element for the determination of the screw-in depth of the screw-in sleeve 22 on the protruding part 3 of the anchor rod 8 of the rock bolt 1. This means that if the pin 36 impacts with its front side onto the front side of the anchor rod 8 of the rock bolt 1, this is then forced from the bore 34. The result is that it falls down and hangs on the arrest wire 37, which is fixed over a ring fastener 38 on the strap 42.

In this way the person who implements the screwing on of the anchor device 20 can identify that the anchor device 20 is connected with the anchor rod 8 over the necessary number of turns of the thread, in particular four.

REFERENCE LIST

-   -   1 Rock bolt     -   3 End of the anchor rod protruding from the gallery roof     -   4 Anchor nut     -   5 Anchor plate     -   8 Anchor rod     -   10 Gallery roof     -   20 Anchor device     -   22 Screw-in sleeve     -   24 Swirl unit     -   26 Internal thread     -   27 Retaining ring     -   28 Shoulder     -   30 Bolt head     -   34 Bore     -   36 Pin (indication element)     -   37 Arrest wire for pin     -   38 Ring fastener for arrest wire     -   40 Anchor element     -   42 Strap (inset-attachment element)     -   44 Ball bearing 

1. A fastening system of a gallery roof of a route section underground, wherein the fastening system comprises a rock bolt and an anchor device configured to be fastened to the rock bolt, wherein the anchor device is configured to be connected with the rock bolt freely pivoting relative to the rock bolt.
 2. The fastening system according to claim 1, wherein the anchor device comprises a screw-in sleeve configured for connection with the rock bolt.
 3. The fastening system according to claim 2, wherein the anchor device is configured to be connected with the rock bolt through a screw-thread connection.
 4. The fastening system according to claim 2, wherein the anchor device comprises a screw-in sleeve, the screw-in sleeve comprising an internal thread, wherein the screw-in sleeve is configured to be screwed onto a protruding part of an anchor rod of the rock bolt.
 5. The fastening system according to claim 2, wherein the screw-in sleeve comprises a shoulder configured for reception of a sleeve-shaped swirl unit.
 6. The fastening system according to claim 5, wherein the swirl unit indicates comprises an inset-attachment element.
 7. The fastening system according to claim 6, wherein the inset-attachment element is a strap.
 8. The fastening system according to claim 5, wherein a bearing is arranged between the shoulder and the swirl unit.
 9. The fastening system according to claim 5, wherein a bolt head is arranged on the shoulder configured for the bedding of a tool.
 10. The fastening system according to claim 4, wherein the anchor device comprises an indication element configured for the determination of a screw-in depth between the screw-in sleeve and the protruding part of the anchor rod of the rock bolt.
 11. The fastening system according to claim 10, wherein the indication element is a pin.
 12. The fastening system according to claim 11, wherein the pin is in a bore in a bolt head and a shoulder and extends with one end into a hollow space of the screw-ion sleeve.
 13. The fastening system according to claim 10, wherein the indication element is configured to be taken up non-positively by a bolt head or a shoulder of the anchor device.
 14. A fastening system of a gallery roof of a route section underground, comprising: a rock bolt; and an anchor device configured to be fastened to the rock bolt, the anchor device comprising a screw-in sleeve configured for a thread connection with the rock bolt; wherein the anchor device is configured to be connected with the rock bolt freely rotating about a vertical axis relative to the rock bolt without rotating off from the rock bolt.
 15. The fastening system according to claim 14, wherein the screw-in sleeve comprises a shoulder configured for the reception of a sleeve-shaped swirl unit; and wherein a bolt head is arranged on the shoulder configured for the bedding of a tool.
 16. The fastening system according to claim 3, wherein the screw-thread connection is a self-locking screw thread.
 17. The fastening system according to claim 7, wherein the inset-attachment element is configured for the reception of a spring hook of a protective harness.
 18. The fastening system according to claim 8, wherein the bearing is at least one bearing selected from the group consisting of an axial ball bearing and a plain bearing.
 19. The fastening system according to claim 12, further comprising an arrest wire configured to catch the pin; wherein the arrest wire is held with a ring fastener to the anchor device.
 20. A method of attaching to a gallery roof of a route section underground, comprising: fastening with the system of claim 6, the fastening comprising; screwing the anchor device onto a threaded piece of the rock bolt extending beyond the rock; and connecting a spring hook to the inset-attachment element. 